Programme Plan & Complementary Documents

MHHS Replan: CR022 Level 1 Milestones approved by Ofgem 

At the Programme Steering Group (PSG) meeting on 8 June 2023, Change Request CR022 was fully approved, following Ofgem's approval of Level 1 milestone changes. This marks a significant step forward for the MHHS Programme.

PSG members agreed that version 5.0 of the MHHS Programme Plan would be adopted as the baseline change. As a live document, PSG members were made aware of specific changes to the plan since CR022 was issued for Impact Assessment.

The MHHS Programme Plan (in Microsoft Project and Microsoft Excel formats), MHHS Milestone Register and MHHS Implementation Approach have been updated in line with the PSG CR022 approved plan. You can view all these documents below, along with the latest Release Note to highlight the changes since the last release.

Key milestone changes were discussed at the Migration & Cutover Advisory Group (MCAG) meeting on 4 June 2024 which are included in the release to provide a detailed view of approved changes in v5.26 of the Programme Plan, and which you can view below.

MHHS Programme Plan (baselined MS Project)

MHHS Programme Plan (Excel format)

MHHS Milestone Register (baselined)

Key Milestone Changes at 28 May 2024

Programme Plan Release Note

MHHS Implementation Approach

Programme Planning Advisory Notes

The Programme provide fortnightly releases of the Programme Plan. The first release was published on 21 June 2023 and you can view these latest documents above, in both Microsoft Project (.mpp) and Excel (.xls) formats. These are accompanied with a guide to interpreting the plan in both formats, with tips on how to easily identify changes since the previous plan.

On 5 July 2023 the Programme Plan was updated to reflect the movement of the interfaces code drafting topic area which now aligns with transition text after approval at the Cross-Code Advisory Group (CCAG) on 28 June 2023.

Additionally, there have been minor updates to the Implementation Approach document which are set out in the update sheet with version 3.2.

If you have any questions, please email [email protected]



Where you can find CR022 and supporting information

You can view Change Request CR022 and the MHHS Implementation Approach document below.

The CR references MHHS Programme-related Artefacts which set out decisions and other factors shaping the proposed plan.

Replan Change Request Form Parts A, B & C (CR022)

MHHS Implementation Approach

If you have any questions on CR022, please email [email protected]

Baselined MHHS Implementation Timeline

Following Programme Steering Group’s (PSG) approval of Change Request CR022: MHHS Programme Replan on 8 June 2023 and Ofgem’s subsequent decision to approve changes to Level 1 milestones, the Programme has updated the Baselined MHHS Implementation Timeline which you can view below:

Baselined MHHS Implementation Timeline

This updated timeline replaces the previous timeline dated 18 May 2022, which was issued following approval of Change Request CR009: M3 & M5 milestone date changes.

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decision group

CR022 Playback Sessions to support the Impact Assessment

In April, the Programme ran Playback sessions to walk through the CR and rationale.

All Playback sessions were recorded and you can view the slides and recordings for all the Playback sessions on the Replan Playbacks page of this website.

If you have any questions on CR022, please email [email protected]

Replan Consultation Q&A

We have complied a list of questions raised in Rounds 1,  2 and 3 of the Programme Replan consultation which you can view below:

Replan Consultation Round 1 & 2 Q&A 

Replan Consultation Round 3 Q&A



Ofgem Settlement Reform Programme Plan

Ofgem published its Market-wide Half-Hourly Settlement: Decision and Full Business Case paper on 21 April 2021 which included the MHHS Transition Timetable.

The Transition Timetable has since been updated and is now owned by the MHHS Programme.